Sumner County climate

Sumner County Frost Dates and Growing Season

NOAA 1991-2020 normals for Bethpage 1 S, 12.2 km from Sumner County, elevation 560 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Bethpage 1 S. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around April 16 and the first fall freeze around October 23, a growing season of about 189 days.

Median at 36°F
last April 28, first October 15
Median at 32°F
last April 16, first October 23
Median at 28°F
last April 3, first October 31

Last freeze in spring

The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.

Threshold10%20%30%40%50%60%70%80%90%
36°FMay 11May 6May 3Apr 30Apr 28Apr 25Apr 21Apr 17Apr 13
32°FMay 2Apr 27Apr 22Apr 19Apr 16Apr 12Apr 9Apr 6Mar 31
28°FApr 20Apr 14Apr 9Apr 5Apr 3Mar 31Mar 28Mar 23Mar 17
24°FApr 8Apr 3Mar 31Mar 28Mar 24Mar 19Mar 15Mar 10Mar 3
20°FMar 31Mar 24Mar 17Mar 14Mar 10Mar 5Mar 1Feb 25Feb 17
16°FMar 17Mar 11Mar 6Mar 1Feb 26Feb 21Feb 15Feb 8Jan 31

First freeze in fall

The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.

Threshold10%20%30%40%50%60%70%80%90%
36°FOct 3Oct 6Oct 10Oct 12Oct 15Oct 17Oct 20Oct 23Oct 26
32°FOct 10Oct 14Oct 17Oct 21Oct 23Oct 25Oct 28Nov 1Nov 4
28°FOct 18Oct 22Oct 25Oct 28Oct 31Nov 2Nov 5Nov 9Nov 15
24°FOct 27Nov 1Nov 4Nov 7Nov 10Nov 14Nov 18Nov 24Dec 1
20°FNov 5Nov 11Nov 16Nov 20Nov 25Nov 29Dec 3Dec 7Dec 17
16°FNov 17Nov 25Dec 1Dec 4Dec 8Dec 13Dec 20Dec 28Jan 3

Growing season length

Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.

Threshold10%20%30%40%50%60%70%80%90%
36°F190183179174171167163158151
32°F210202197193189184181176170
28°F233224218214210206201197188
24°F257249243237232227222217210
20°F288278270263257253247240231
16°F322310302295288280274266256

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
100% of years
32°F or colder
100% of years
28°F or colder
100% of years
24°F or colder
100% of years
20°F or colder
100% of years
16°F or colder
100% of years

Degree days

A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.

Heating degree days, base 65°F
4,293
Cooling degree days, base 65°F
1,289
Growing degree days, base 40°F
6,717
Growing degree days, base 45°F
5,328
Growing degree days, base 50°F
4,093
Growing degree days, base 55°F
3,010
Growing degree days, base 60°F
2,077

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January922017
February730023
March568379
April29116221
May9297472
June5257702
July0377842
August1340804
September36171585
October26327261
November566162
December819024

What this means

NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.

The station is 12.2 km from Sumner County. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

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Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00400669 (Bethpage 1 S). Public domain.